1204.0512
Correlated gravitational wave and neutrino signals from general-relativistic rapidly rotating iron core collapse
Ott, et al
3D GR hydro sum of rotation Fe core collapse with octant symmetry; focus on axisymmetric collapse, bounce, the early post bounce evolution, and the associated GW and neutrino signals. Finite temperature nuclear equation of state, parameterized electron capture, multi-species neutrino leakage after bounce. Consider 12 and 40 Msun progenitor and systematically study effects of (i) rotation, (ii) progenitor structure, and (iii) post bounce neutrino leakage on dynamics, GW and neutrino signals. Demonstrate GW signal of rapidly rotating core collapse is independent of progenitor mass and pre collapse structure. Effects of neutrino leakage on GW signal strong only in non rotating or slowly rotation models, in which GW emission is not dominated by inner core dynamics. In rapidly rotating cores, core bounce of the centrifugally-deformed inner core excites the fundamental quadrupole pulsation mode of the nascent protoneutron star; ensuing global oscillations (f~700-800 Hz) lead to pronounced oscillations in the GW signal and correlated strong variations in the rising luminosities of antineutrino and heavy-lepton neutrinos. Find these features in cores that collapse to protoneutron stars with spin periods <2.5 ms and rotation energies sufficient to drive hyper-energetic dore-collapse SNe explosions. Hence, going GW+neutrino observations of a core collapse event could deliver strong evidence for or against rapid core rotation.
1204.0514
Multiple dark matter as a self-regulating mechanism for dark sector instructions
Baldi
As the title says. Two types of DM, but interaction "charge" with DE differs.
1204.0515
Size matters: the non-universal density profile of subhaloes in SPH simulations and implications for the Mikly Way's dSphs
Di Cintio, Knebe, Libeskind, Brook, Yepes, Gottloeber, Hoffman
Hydro sim on formation of the Local Group (CLUES), study density profile of sub haloes of MW and Andromeda. Einasto model provides the best description; its shape parameter strongly correlated with the total subhalo mass (non-universailty of density profile). Improve observational constrains on Rmax-Vmax pairs for the brightest satellite galaxies of the MW. Consider only the sub haloes with -13.2 < M_V< -8.8 (classical dwarf range), find all simulated objects consistent with the observed dSphs if they follow Einasto model with 1.6<nE<5.3. Numerically motivated Einasto profile for the observed dSphs as well as the observationally motivated magnitude cut for the simulated sub haloes will eliminate the "massive failures" problem and results in agreement with observations.
1204.0516
The growth of galactic bulges through mergers in LCDM haloes revisited. I. Present-day properties
Zavala, Avila-Reese, Firmani, Boylan-Kolchin
Simulate bulge formation due to mergers; reproduces bulge/total ratio of today, although bulge less galaxies (B/T<0.1) galaxies scarce relative to observed abundance [probably because it's not considering gas stream-feeding of galaxies]. In the merger-driven scenario, bulge population is made of (i) stars acquired from in falling satellites, (ii) stars transferred from the primary disc due to the perturbations from merging, (iii) newly formed stars in starbursts triggered from mergers. (i) dominant for massive galaxies, creates large bulge, heterogeneous stellar population, (ii) dominant for intermediate galaxies, homogeneous stellar population than inner disc. ... morphology.
1204.0517
Detecting gravitationally lensed population III galaxies with HST and JWST
Zackrisson, Zitrin, Trenti, Rydberg, Guaita, Schaerer, Broadhurst, Ostlin, Strom
Detect z~7-17 Pop III star galaxies with J0717 cluster, from the CLASH survey (HST).
1204.0524
Converting from 3.6 and 4.5 micron fluxes to stellar mass
Eskew, Zaritsky, Meidt
As the title says. Works on LMC.
1204.0658
The small-scale dynamo and non-ideal MHD in primordial star formation
Schober, Schleicher, Federrath, Glover, Klessen, Banerjee
* Biermann battery: An astrophysical process in which weak seed B-field can be generated from zero initial conditions. Relative motion between electrons and ions is driven by rotation.
Assume weak B-field seed generated by the Biermann batter process, both Burgers and Kolmogorov turbulence lead to saturation within a rather small density range. Such fields are likely to become relevant after the formation of a protostellar disk and, thus, could influence the formation of the first stars and galaxies in the universe.
1204.0762
Sodium atoms in the lunar exotail: observed velocity and spatial distributions
Line, Mierkiewicz, Oliversen, Wilson, Haffner, Roesler
The lunar sodium tail extends long distances due to radiation pressure on sodium atoms in the lunar exosphere. Averate radial velocity of Na atoms moving down the lunar tail beyond Earth (near the anti-lunar point) is ~12.5 km/s. Use Wisconsin H-alpha mapper to obtain the kinematically resolved maps of the intensity and velocity distribution of this emission over a 15x15deg region on the sky near the anti-lunar point. Modeling suggest that spatial and velocity distributions in the sodium exotail are sensitive to the near surface lunar sodium velocity distribution.
1204.0763
Effects of radiation on primordial non-Gaussianity
Das
Study non-Gaussian features in single-field slow-roll inflationary scenario where inflation is preceded by a radiation era, in which case both bispectrum and trispectrum non-Gaussianities are enhanced. Trispectrum does not depend on the slow-roll parameters, and thus tau_NL is larger than f_NL which can be a signature of a pre-inflationary radiation era.
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